The Cleaner is coming . . .

dallasjustice

Member Sponsor
Apr 12, 2011
2,090
0
0
Dallas, Texas
#1
Not that Cleaner:
the cleaner.JPG

This is it:
cleaner front.JPG cleaner back.JPG


Digital audio reproduction has many believers and I am definitely one of them. To this day, even the best DtoA converters have their weaknesses. We hear differences never thought possible with ever lower levels of clock phase noise. We can hear small differences between different DtoA chips or discrete FPGA converters. At some point, one wonders whether there's a different way to deal with nonlinearities that ALL DACs produce. Dr. Uli Brueggeman has been thinking about these problems for some time. We've previously discussed his method of introducing frequency dependent crosstalk. You can read more about that here:
http://www.whatsbestforum.com/showthread.php?15471-Crosstalk-digital-more-like-Vinyl

The idea is to introduce frequency dependent crosstalk so as to reduce the load on the brain when decoding phantom sources. The result can be a more relaxed listening experience and even better stereo imaging. The "Cleaner" was developed to address the difficulties of localization. In particular, the "Cleaner" is designed to deal with left/right nonlinearities produced by the DAC. The theory according to Uli is that any small nonlinearity between the R/L channels stresses the brain which is attempting to localize the phantom sources while listening to a stereo image. In the worst case scenario, if left and right channel do not correlate our brain has to do a lot of decoding work.

The "Cleaner" is a mid/side analog decoder designed to high quality standards. The signal in the digital domain is converted into a mid/side pair of channels and sent out the DAC into the "Cleaner." The "Cleaner" then decodes it in the analog domain. (analog in and analog out, 1:1 gain, low output impedance output).

Mid/side encoding is not new technology. It's become very popular these days with many mastering engineers. Of course, they are using it for a completely different purpose. Mastering engineers can use mid/side to enhance spatiousness and adjust vocal in middle of the stereo image. The "Cleaner" does not change the original waveform.

In Uli's words, here's how mid/side encoding and decoding work to reduce any nonlinear distortion caused by the DAC:

"m/s processing means:
M = (L+R)/2
S = (L-R)/2
Then you can reconstruct L/R by
L = M+S
R = M-S
If the processing is perfect then you get the original signals back. This is the intention. There is no reason to change the original content (whereas with mixing and mastering there is a tradition to apply m/s processing with changes of M and S)
Now assume that during DA conversion you get some signal dependent dirt. So you may get
Lanalog = Ldigital + Ldirt
Ranalog = Rdigital + Rdirt
Ldirt and Rdirt do not necessarily correlate.
Now instead of feeding the DAC with Ldigital and Rdigital you feed it with
Mdigtal = (Ldigital+Rdigital)/2
Sdigital = (Mdigital - Rdigital)/2
The analog signal thus is
Manalog = Mdigital + Mdirt
Sanalog = Sdigital+Sdirt
Mdirt and Sdirt do not necessarily correlate.
With m/s decoding now you get
Lanalog = Manalog+Sanalog = (Migital+Sdigitla) + (Mdirt+Sdirt) = Ldigital + (Mdirt+Sdirt)
Ranalog = Manalog-Sanaog = (Mdigital-Sdigital) + (Mdirt-Sdirt) = Rdigital + (Mdirt-Sdirt)
So the output signal is the original signal plus dirt again. We cannot avoid the dirt. But now the resulting dirt on left and right side has some correlation as both sides contain Mdirt and Sdirt.

In reality the decoding circuit cannot be expected to be 100% perfect, it will also add some crosstalk. As we have learnt from flow the crosstalk is not necessarily bad. Anyway the decoding circuit has to be designed carefully.
So you understand, the basic idea is very, very simple. But is has never been published before. So I have built a prototype and I have been excited by the result. Then I have got the chance to visit ABACUS for a three day workshop for demostrating Acourate. I have decided to test the prototype by demonstrating its function to the people. It has been a full success. The audience has finally baptized the circuit as "cleaner". And ABACUS and I decided to start a product AcourateCleaner."

I have tried many preamps over the years. They were all some of the best out there. Everytime, I felt that the preamp reduced resolution compared with my DAC direct to amp. So, I've never used a preamp. The "Cleaner" is not a preamp. It simply decodes the m/s signal back into original 2CH signal and drives the amps from it's low impedance output. What does it sound like?

The image is wider and more spacious. The usually harsh recordings are rendered more relaxed with increased detail retrieval. The really incredible improvement is with vocal located at the middle of the soundstage. Voices are deeper, more natural, more articulate and much more relaxed sounding. I highly recommend it for digital folks searching for a more analog feel to their favorite music.

Michael.
 
Last edited:
#2
Well I don't know how necessary this is. I do know when doing difference testing to compare audio interconnect, the difference between right and left channels of even high quality DACs is some 10 decibels higher than between interconnect on the same channel. Of course basically interconnect differences are down in the thermal noise floor and channel differences are just out of it. I have my doubts it really is audible, but it is a real effect.
 
Dec 12, 2012
243
0
16
#5
"... And ABACUS and I decided to start a product AcourateCleaner."

Does the above statement mean that you have a financial interest in the commercial success of this product?
 

dallasjustice

Member Sponsor
Apr 12, 2011
2,090
0
0
Dallas, Texas
#6
"... And ABACUS and I decided to start a product AcourateCleaner."

Does the above statement mean that you have a financial interest in the commercial success of this product?
Those are Uli's words. That's why it's preceded with "in Uli's words" and the part you tried to quote was originally in quotation marks. Therefore, you should have used ' instead or " to signify the original in quotes. :p
 
Mar 20, 2011
58
0
6
North Texas
#7
I am fortunate to have stumbled upon this thread when I did because I am finishing up a new DAC design and adding the option of M/S decoding to the output circuit is trivial and adds little additional cost. Incorporated in the DACs output stage is where it belongs; not in an external box with a power supply, active circuits, and additional interconnects.

Of the two stereo image enhancers, Acourate Cleaner and Acourate Flow, which do you prefer and have you found value in using them together?
 

dallasjustice

Member Sponsor
Apr 12, 2011
2,090
0
0
Dallas, Texas
#8
I like the cleaner better. I've found the flow to be an improvement only sometime. The cleaner makes image clarity much better with all music.

I agree an m/s decoder could be very helpful at DAC output stage. However, no commercial MCH DAC/ADC has one and the lynx hilo is otherwise perfect for my application wherein I use 4CH and DSP filters for active crossover, delay and room correction.

Tell me more about your DAC.


I am fortunate to have stumbled upon this thread when I did because I am finishing up a new DAC design and adding the option of M/S decoding to the output circuit is trivial and adds little additional cost. Incorporated in the DACs output stage is where it belongs; not in an external box with a power supply, active circuits, and additional interconnects.

Of the two stereo image enhancers, Acourate Cleaner and Acourate Flow, which do you prefer and have you found value in using them together?
 
Last edited:
Mar 20, 2011
58
0
6
North Texas
#9
Tell me more about your DAC.
I don't want to hijack your thread with tales of my 'paper' DAC...But since you asked... I'll share a few highlights that involve coordinating DAC and PC-based DSP functions. The DAC uses a proprietary USB transfer protocol and will require a companion player in order to function. The player can resample, apply sinc compensation, convolutions, and most other common DSP operations, in real time, as directed by the audio fille's metadata. The metadata is also passed to the DAC.

So, the application of M/S encoding would work as follows: If the default setting of the player is to use M/S or the file had a M/S tag, the player would perform the encoding and send the M/S tag to the DAC which would then do the decoding. Simple, yet effective.
 
Last edited:

dallasjustice

Member Sponsor
Apr 12, 2011
2,090
0
0
Dallas, Texas
#10
What is the reason/hope for adding ms decoding output stage?

I don't want to hijack your thread with tales of my 'paper' DAC...But since you asked... I'll share a few highlights that involve coordinating DAC and PC-based DSP functions. The DAC uses a proprietary USB transfer protocol and will require a companion player in order to function. The player can resample, apply sinc compensation, convolutions, and most other common DSP operations, in real time, as directed by the audio fille's metadata. The metadata is also passed to the DAC.

So, the application of M/S encoding would work as follows: If the default setting of the player is to use M/S or the file had a M/S tag, the player would perform the encoding and send the M/S tag to the DAC which would then do the decoding. Simple, yet effective.
 
Mar 20, 2011
58
0
6
North Texas
#11
What is the reason/hope for adding ms decoding output stage?
Gee, I don't know. I came across a thread in an audio forum where the OP was describing the benefit of using "The Cleaner", a device that added M/S decoding to the output of a DAC after the input to the DAC was M/S encoded. It sounded interesting but I didn't want to shell out big bucks for the device and even more big bucks for additional interconnects and power cord just to try it.

Then I remembered I had a DAC design on the drawing board that could easily be enhanced to include M/S processing. I figure the added cost would be $15 for hardware and $0 for software. If I liked the result I could turn the feature on or off globally or on a track by track basis with the click of the mouse.
 

dallasjustice

Member Sponsor
Apr 12, 2011
2,090
0
0
Dallas, Texas
#12
Sounds like you put a lot of thought into it. Enjoy your paper DAC.


Gee, I don't know. I came across a thread in an audio forum where the OP was describing the benefit of using "The Cleaner", a device that added M/S decoding to the output of a DAC after the input to the DAC was M/S encoded. It sounded interesting but I didn't want to shell out big bucks for the device and even more big bucks for additional interconnects and power cord just to try it.

Then I remembered I had a DAC design on the drawing board that could easily be enhanced to include M/S processing. I figure the added cost would be $15 for hardware and $0 for software. If I liked the result I could turn the feature on or off globally or on a track by track basis with the click of the mouse.
 

zydeco

New Member
Oct 16, 2010
58
0
0
WA, Australia
#14

dallasjustice

Member Sponsor
Apr 12, 2011
2,090
0
0
Dallas, Texas
#15
I'm still using it. I like it. It's not a huge difference in my system. It's just one of those small but noticeable improvements. There's no downside to using it in my system.

Your update caught my attention as a user of acourate [for digital x/o and room eq. purposes]. What is your feeling about the cleaner after extended time with the approach?
 

marty

Active Member
Apr 20, 2010
1,108
4
38
Far Hills, NJ
#16
Interesting thread but I'm confused. If I understand this correctly, the Cleaner works by adding frequency dependent crosstalk which is supposed to result in better imaging ("wider and more spacious"). Ok, but recently, we've been reading about Bacchus, a device which claims to improve imaging to the point of recreating 3-D imaging as if it were the real event, by reducing crosstalk. These principles and devices seem diametrically opposed to each other. Can someone explain this to me? Am I missing something? Thanks in advance.
Marty
 

dallasjustice

Member Sponsor
Apr 12, 2011
2,090
0
0
Dallas, Texas
#17
The cleaner isn't really about frequency dependent crosstalk. You want to read the first post where I quote Uli's description. I mentioned Acourate "flow" in another thread which does introduce FDC. Personally, I don't use Acourate flow. The cleaner is designed address DAC nonlinearities between channels. I shouldn't have mentioned the flow in the first post.

I asked Uli your question a couple of weeks ago on the Acourate forum. I know that Uli is fully informed about what the BACCH does which is similar to previous attempts at crosstalk cancellation. Maybe Uli would be so kind as to chime in here since I agree with you that it's an interesting dichotomy.
Michael.


Interesting thread but I'm confused. If I understand this correctly, the Cleaner works by adding frequency dependent crosstalk which is supposed to result in better imaging ("wider and more spacious"). Ok, but recently, we've been reading about Bacchus, a device which claims to improve imaging to the point of recreating 3-D imaging as if it were the real event, by reducing crosstalk. These principles and devices seem diametrically opposed to each other. Can someone explain this to me? Am I missing something? Thanks in advance.
Marty
 
Last edited:
Nov 3, 2014
405
0
0
#18
Interesting thread but I'm confused. If I understand this correctly, the Cleaner works by adding frequency dependent crosstalk which is supposed to result in better imaging ("wider and more spacious"). Ok, but recently, we've been reading about Bacchus, a device which claims to improve imaging to the point of recreating 3-D imaging as if it were the real event, by reducing crosstalk. These principles and devices seem diametrically opposed to each other. Can someone explain this to me? Am I missing something? Thanks in advance.
Marty
I think part of the problem with trying to create a more spacious image from a stereo source, is that the amount of spatial information on the disc is limited by miking, mixing and mastering in the first place. If it were not, the sound would be "too cavernous" and distant sounding. There is also the problem of redirecting the surrounding hall sound at you from just two stereo speakers up front. Also, studio recordings have no natural space: it is created via panning and adding things like artificial reverb.

I have not heard the Cleaner or the new Chouieri device, but I have heard recordings using the Blumlein stereo mike technique. Blumlein was also a "theoretically perfect" way to generate "realistic" immersive space in the recording. As a classical listener intent on recapturing the sound of a live performance in the hall, I strongly favor hi rez Mch. I have thousands of discs in that format that are, for me, the closest approach to live sound in the hall that I have heard by far.
 
May 19, 2014
693
0
16
Round Rock, TX
#19
Also, studio recordings have no natural space: it is created via panning and adding things like artificial reverb.
I partially disagree with your statement. The recording space does indeed have natural space which can and sometimes does come across in recordings (think the Trinity Sessions, live recordings). However, as you eluded to earlier it is not reproduced as omni-direcional unless the recording is available in multi-channel. Basic recording techniques such as panning and reverb only augment the recordings' natural space and should be used sparingly or the results are typically less than realistic.
 

About us

  • Founded in 2010 What's Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals we enjoy learning about new things and meeting new people and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing